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Tagged: danger

Halloween is a great time for makers, we get to make all kinds of cool costumes and spooky things. Sometimes we get to play with fire. Well at least Chris Lee does. This flaming pumpkin is enough to keep them pesky kids from toilet-papering your house, or catching it on fire after they do.

The pumpkin is triggered by an Android phone, talking to a RFU-328 radio and Arduino. The Arduino triggers 2 relays, 1 to activate a furnace igniter, the other activates a solenoid that releases the flow of gas. The spray mechanism comes from an AirWick room spray and is filled with butane.

Chris made a comment about maybe converting this to shoot silly string out during actual Halloween, either way it’s a cool project.

Following the same idea as this previous post, it I stumbled on this company that has the same concept for turning your 3D Printer into a low power laser cutter/engraver. They appear to actually have a kit ready to go now which seems to focus primarily on the old Makerbot thing-o-matic, but I’m sure can be adapted to other designs.

The laser is mounted in front of the plastic extruder, and the 2 watt laser driver board is tied to the motor on/off signal from the existing electronics. From there a little special G code is required to get it going .

Check out a video of it cutting 1/32″ wood with a 445nm Blu Ray laser after the break.

It’s Friday… and you are probably are stuck at work. So why not learn how to remove a IC from a PCB — in a very very unconventional way. It’s great if you don’t care about the chip… or the board for that matter.

Seriously though, if you need to relieve some stress, the guys who made this video Electronics In a Nutshell have a very entertaining channel on YouTube where they mostly torture circuit boards and stuff in various ways. Just the way we like it.

Here’s another entertaining video to get you through the day. Lithium-Ion battery vs 220 volts.

I’m sure everyone has thought of it, but is anyone actually doing it ? It’s a work in progress, but up on thingiverse is a universal mount, some schematics, and Arduino code for adding a laser to your 3D Printer. Why not? You’ve already got an XYZ platform… The build so far is made to be minimally intrusive to modifying your printer. e.g. you don’t have to modify your printer’s firmware.

Before you go rushing off and strap a laser to your extruder, note that even very low power lasers are real dangerous. Don’t fool around with safety.

With that being said, the build works like this. The laser controller is an arduino setup to control a low power laser (sorry no giant 40w laser tubes guys!). We’re looking at 1W-5W. This should be enough to do some small engraving. A small DC motor is attached with a universal bracket and attached to the extruder. It’s tied to the extruder so when the stepper motor turns, the dc motor turns. The motor is read via the analog port on the Arduino. Code-wise, if the voltage exceeds the threshold voltage the laser will fire.

Right now it’s just breadboarded and not working but I’m interested to see how this plays out.

! WARNING !

Dealing with mains voltage is no joke, please be careful

Running your LEDs from AC voltage is pretty efficient, you can light up a whole lot of LEDs with little effort. Most Christmas lights you buy nowadays already do this, but as Matt points out in the video they flicker a lot. Matt decided to set up a bridge rectifier, and a capacitor to smooth out the flickering. As shown on the oscilloscope those simple modifications make a huge improvement!

Of course you can’t just plug the LEDs into the wall and expect it to work (and not catch fire). A little planning is needed. By calculating the collective voltage drop of the LEDs in series you can run a lot of LEDs with very little current limiting. Cool hack Matt.